Edward b



(No Mddel.)

. E. B. HATGH 8v 0. A. COLTON.

ELEGTRO MAGNET BOBBIN.

No. 479,804. Patented Aug. 2, 1892.

E J E :1

UNITED STATES PATENT OFFICE.

EDVARD B. HATCH AND CHARLES A. COLTON, OF HARTFORD, CONNECTICUT,

ASSIGNORS TO THE JOHNS-PRATT COMPANY,

OF SAME PLACE.

ELECTRO-MAGNET BOBBIN.

SPECIFICATION forming part of Letters Patent No. 479,804, dated August 2, 1892. Application filed January 13, 1892. Serial No. 417,921. (No model.)

T to whom it may concern.-

Be it known that we, EDWARD B. HATCH and CHARLES A. OoLToN, citizens of the United States, residing at Hartford, in the county of Hartford and State of Connecticut, have invented certain new and useful Improvements in Magnet-Bobbins, of which the following is a full, clear, and exact specification.

The invention relates to the class of artilo cles which are intended to be slipped upon cores for holding the helices or windings of Wire of electro-magnets, the object being to provide a cheap bobbin of this class made lightly in a single piece of the exact size to I 5 receive the correct amount of winding and be easily slipped on the core, more particularly of a field-magnet, which will have strength to resist fracture or rupture and sustain considerable weight, have high-insulating and heat-resistingqualities, will not change shape or buckle under the heating effects nor when subjected to moisture, be capable of standing the deleterious action of water, acids, and alkalies without special treatment, and will offer no attractive path for the passage of a current from one coil to another to burn out the winding.

Referring to the accompanying drawings, Figure 1 is a view of a magnet with bobbins holding the helices. Fig. 2 is an edge view of a bobbin embodying the improvements. Fig. 3 is a face view, and Fig. 4 is a section,

, of the same.

In the views, 1 indicates the leg or core of any species of permanent or electro magnet, and 2 the bobbin which holds the helices 3, of wire, through which passes the magnetizing-current. This bobbin is made in a single piece, of an india-rubber and asbestus 4o composition, with a body 4, having an opening 5, of a size and shape that permits the bobbin to be slipped on the core, and thin flanges 6 at the ends of the body of a proper height to receive and hold the desired nu mber of turns of the wire.

In the processes of manufacture asbestus, preferably long-combed fibers, with or without a body or filling, is thoroughly incorporated with a binder composed of a mass of gum,

as india-rubber, shellac, or a similar resinous 5o substance, with or without a hardening agent. Usually asbestus, india-rubber, and sulphur thus incorporated is molded to the shape of the bobbin, and then placed in dies and subjected to a high heat and great pressure, which byvulcanization and pressure solidifies, hardens, and strengthens the mass. The whole bobbin may be molded at first in a single piece or the body and the flanges molded separately and joined by a vulcanizable cement and then united into a single integral piece by vulcanization in molds under heat and pressure. Bobbins thus formed, although efficient for all classes of magnets, are particularly applicable for the field-magnets of railway and other large motors which are exposed and subjected to the action of the elements and at times run through water that in mines often contains solutions of acids and alkalies, for the reason that moisture, 7o acids, and alkalies have no effect upon the asbestus and rubber composition, and thus do not affect the insulating qualities so as to afford a path for the magnetizing current from one coil to another, nor will the flanges soften so as to let down the wire which is very heavy, nor will they buckle and throw the coils out of shape and place. A bobbin made of this material in this manner is very light, is cheaply made in dies in a single piece of an exact size to closely fit upon the core or leg of the magnet for which it is designed, and so that the exact amount of wire may be 'wound upon a number from a winding apparatus without change when once adjusted, while the asbestus fibers make the bobbin very strong, rigid, and capable of sustaining the weight of a large amount of wire, which is necessary when the magnet is put in certain positions and the weight of the wire comes on the thin flanges of the bobbin. This bobbin is strongly made in a single piece. There are no cemented parts to give way when subjected to moisture, nor are there any openings in which moisture can collect and stand. 5 It is of very high insulating capacity, does not absorb moisture and become soft, neither does it become soft nor warp, buckle, or twist under heat, and it will stand a high degree tus composition in a single piece, and helices 10 of heatwithout affecting its non-conductivity, of wire wound about the bobbin between the allowing it [0136 used in places Where metal flanges, substantially as specified.

bobbins or bobbins made up of pieces could not be placed. EDWARD B. HATCH.

\Ve claim as our invention CHARLES A. OOLTON. In an electro-inagnet,in combination, a me- Witnesses: tallic core, a bobbin with projecting flanges of H. R. WVILLIAMS,

partially-vulcanized india-rubber and asbesl H. H. BURDIOK. 

